Overview
The NCP4318ALCDR2G is an advanced synchronous rectifier (SR) controller designed by onsemi for use in LLC resonant converters. This controller is optimized for high-efficiency power supplies with minimal external components. It features two independent gate driver stages, each with dedicated drain and source sensing inputs, to drive the SR MOSFETs rectifying the outputs of the secondary transformer windings. The NCP4318ALCDR2G incorporates advanced adaptive dead time control and a mixed-mode SR turn-off control algorithm to ensure stable SR operation across the entire load range, maximizing system efficiency and reliability.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VDD Power Supply Input Pin Voltage | -0.3 | 37 | V | |
| VD1, VD2 Drain Sense Input Pin Voltage | -4 | 200 | V | |
| VGATE1, VGATE2 Gate Drive Output Pin Voltage | -0.3 | 17 | V | |
| VS1, VS2 Source Sense Input Pin Voltage | -0.3 | 5.5 | V | |
| VDD Turn-on Threshold | 4.0 | 4.3 | V | |
| VDD Turn-off Threshold | 3.6 | 3.8 | V | |
| Operating Junction Temperature | -40 | 125 | °C | |
| Switching Frequency Range | 22 kHz | 500 kHz | ||
| Gate Sourcing and Sinking Current | 1.5 A / 4.5 A | |||
| Package Type | SOIC-8 EP (Pb-Free) |
Key Features
- Mixed Mode SR Turn-off Control
- Anti Shoot-through Control for Reliable SR Operation
- 200 V-rated Drain Sensing and Dedicated Source Sensing Pins
- Advanced Adaptive Dead Time Control
- SR Current Inversion Detection
- Adaptive Minimum Turn-on Time for Noise Immunity
- SR Conduction Time Increase Rate Limitation
- Multi-level Turn-off Threshold Voltage
- Adaptive Gate Voltage (10 V, 6 V)
- Low Operating Current (100 μA) in Green Mode
- Soft Start with 0 V / 6 V Gate Output Voltage
- Short Turn-on and Turn-off Delay Time (30 ns / 30 ns)
- High Gate Sourcing and Sinking Current (1.5 A / 4.5 A)
- Wide Operating Supply Voltage Range from 6.5 V to 35 V
Applications
- High Power Density Adapters
- Large Screen LED-TV and OLED-TV Power Supplies
- High Efficiency Desktop and Server Power Supplies
Q & A
- What is the primary function of the NCP4318ALCDR2G?
The NCP4318ALCDR2G is an advanced synchronous rectifier controller designed for LLC resonant converters, optimizing power supply efficiency. - What types of sensing inputs does the NCP4318ALCDR2G have?
The controller has dedicated drain and source sensing inputs for each SR MOSFET. - What is the operating supply voltage range of the NCP4318ALCDR2G?
The operating supply voltage range is from 6.5 V to 35 V. - What is the switching frequency range of the NCP4318ALCDR2G?
The switching frequency range is from 22 kHz to 500 kHz. - What are the key features of the NCP4318ALCDR2G's gate drivers?
The gate drivers have high sourcing and sinking currents (1.5 A / 4.5 A) and short turn-on and turn-off delay times (30 ns / 30 ns). - How does the NCP4318ALCDR2G manage dead time?
The controller uses advanced adaptive dead time control to regulate the dead time between the SR MOSFETs, compensating for parasitic inductance and maximizing system efficiency. - What are the typical applications of the NCP4318ALCDR2G?
Typical applications include high power density adapters, large screen LED-TV and OLED-TV power supplies, and high efficiency desktop and server power supplies. - What is the package type of the NCP4318ALCDR2G?
The package type is SOIC-8 EP (Pb-Free). - Does the NCP4318ALCDR2G support green mode operation?
Yes, it operates in green mode with a low operating current of 100 μA. - What is the operating junction temperature range of the NCP4318ALCDR2G?
The operating junction temperature range is from -40°C to 125°C.
